Method of making a catheter balloon using a polyimide covered mandrel

Abstract

A method of making a catheter balloon or other tubular medical device or component, in which a sheet of polymeric material is wrapped on a mandrel and heated to fuse sections of the wrapped sheet together to form a tube. The mandrel has a metallic core and a jacket on an outer surface of the metallic core, and the wrapped sheet of polymeric material is heated without corroding the metallic core of the mandrel. In a presently preferred embodiment, the sheet is formed of a fluoropolymeric material, and the resulting fluoropolymeric tube forms at least a layer of a catheter balloon.

1. A method of making a tubular medical device or component formed of a fluoropolymeric material, comprising:
 a) wrapping a sheet of a fluoropolymeric material on a mandrel, the mandrel having a metallic core and a jacket of a polyimide material on an outer surface of the metallic core;  
 b) heating the wrapped sheet of fluoropolymeric material on the mandrel to fuse sections of the wrapped sheet together to form a fluoropolymeric tube; and  
 c) removing the fluoropolymeric tube from the metallic core and the jacket of the mandrel.  
 
     
     
       2. The method of  claim 1  wherein b) comprises heating the wrapped sheet without corroding the metallic core of the mandrel. 
     
     
       3. The method of  claim 1  wherein the fluoropolymeric material of the sheet is expanded polytetrafluoroethylene, and the sheet is spirally wrapped on the mandrel. 
     
     
       4. The method of  claim 1  wherein the metallic core of the mandrel is stainless steel, and b) comprises heating the wrapped sheet in an oven. 
     
     
       5. The method of  claim 1  wherein c) comprises removing the polyimide jacket and the metallic core of the mandrel together from inside the fluoropolymeric tube. 
     
     
       6. The method of  claim 1  wherein c) comprises removing the metallic core of the mandrel from inside the fluoropolymeric tube and removing the polyimide jacket from inside the fluoropolymeric tube after the metallic core of the mandrel is removed therefrom. 
     
     
       7. The method of  claim 1  wherein the medical device component is a catheter balloon and including, after c) securing a liner to the fluoropolymeric tube to form the catheter balloon. 
     
     
       8. The method of  claim 1  wherein the polyimide jacket is a thermoset polyimide having an outer diameter and a length, and b) comprises heating the wrapped sheet at about 350° C. to about 390° C. for about 10 minutes to about 30 minutes. 
     
     
       9. The method of  claim 8  wherein the thermoset polyimide jacket outer diameter before b) is substantially unchanged after b). 
     
     
       10. The method of  claim 8  wherein the thermoset polyimide jacket length before b) is substantially unchanged after b). 
     
     
       11. A method of making at least a layer of a catheter balloon, comprising:
 a) wrapping a sheet of expanded polytetrafluoroethylene on a mandrel, the mandrel having a stainless steel or aluminum core and a thermoset polyimide jacket on an outer surface of the core, the thermoset polyimide jacket having an outer diameter and a length;  
 b) heating the wrapped sheet of expanded polytetrafluoroethylene on the mandrel at a temperature of about 350° C. to about 390° C. to fuse sections of the wrapped sheet together to form an expanded polytetrafluoroethylene tube, without corroding the core of the mandrel and without changing the outer diameter and length of the polyimide jacket; and  
 c) removing the expanded polytetrafluoroethylene tube from the stainless steel or aluminum core and the thermoset polyimide jacket of the mandrel, to form at least a layer of the catheter balloon.  
 
     
     
       12. The method of  claim 11  wherein b) comprises heating the wrapped sheet for about 10 to about 30 minutes in an oven. 
     
     
       13. The method of  claim 11  wherein the thermoset polyimide jacket has a thickness of about 0.025 to about 0.15 mm, and c) comprises removing the core of the mandrel from inside the expanded polytetrafluoroethylene tube and removing the polyimide jacket from inside the expanded polytetrafluoroethylene tube after the core of the mandrel is removed therefrom. 
     
     
       14. A method of making a tubular medical device or component, comprising:
 a) placing a sheet of a polymeric material on a mandrel, the mandrel having a metallic core and a jacket on an outer surface of the metallic core, the jacket having an outer diameter and a length and being formed of a polymeric material with a glass transition temperature of at least about 390° C. to about 420° C.;  
 b) heating the sheet on the mandrel to an elevated temperature of about 350° C. to about 390° C. without changing the outer diameter and length of the jacket; and  
 c) removing the heat treated polymeric material from the metallic core and the jacket of the mandrel.  
 
     
     
       15. The method of  claim 14  wherein the polymeric material of the jacket is a thermoset polymeric material, and b) comprises heating the sheet for about 10 to about 30 minutes. 
     
     
       16. The method of  claim 15  wherein the sheet of polymeric material is expanded polytetrafluoroethylene, and b) comprises heating the sheet at an elevated temperature of about 360° C. to about 380° C. 
     
     
       17. The method of  claim 15  wherein b) comprises heating the sheet on the mandrel without corroding the metallic core of the mandrel.